I believe in rational thinking, critical thinking, and empirical science. Those lead me to explanation of life that does not include gods, and to explanation that humans have social, politica,l and personal agendas that make them falsely believe in and/or falsely promote belief in gods. I don't know where that fits in the scheme of things in this question.

I find this question very hard to interpret. The revised A, "lack of a belief in gods" (and I prefer to use the word "deities" wherever and whenever possible), seems to mean that one does not believe in any of the deities of which one is aware. Or it means just the same thing as B, "the belief that there are no gods". I don't understand what distinction you are trying to draw here. Usually when atheists disagree as to the meaning of atheism, it revolves around whether we are agnostic atheists (we think there are no deities but we don't know for sure) or gnostic atheists (we know there are no such things as deities). You are asking if we look at our beliefs as being negative (lack of a belief) or positive (existence of a belief). This is just two sides of the exact same coin. If you lack a belief in deities, it is because you hold a positive belief in the nonexistence of deities. And vice versa. So D. all of the above.

After further thought, I now believe that this question is still misleading, but for different reasons. I stand by my original distinction; the revised A seems to be the agnostic atheist position that one does not believe in any of the deities of which one is aware, but leaving open the possibility that there may still be a deity of some sort, such as one who may have created the universe, while B seems to be the gnostic atheist position that there are certainly no such things as gods, at least to the degree about which we can be certain of anything. If my interpretation is correct, I am quite astounded by the number of agnostic atheists who have here responded with the revised A! I think there would be far fewer of them if this question were more clear. I therefore change my response to a resounding B and feel compelled to start my own discussion on this topic.